I think the article has some selection bias baked in. It's not really true that bad music disappears and good music remains. It's more like "the very best of music is remembered, everything else is forgotten". Even quite good music is simply discarded as the new trends wash it away, then they just never get rediscovered because they weren't the best, only "quite good".

From the 1952 list, I can name at least three performers who made pretty good music (Ella Mae Morse, Patti Page, Jo Stafford) but not many remember them because they didn't chase the trends. Rock and roll pretty much washed away everything - Ella Mae Morse stopped recording entirely in 1957 after many of her songs didn't sell at all, Jo Stafford was pretty much done by 1960 too. Patti Page held up a bit better but she was also relegated to being a nostalgia act. This is not related to their musical quality or achievements at all, public taste in music simply changed too much. I can list way too many other performers who suffered the same fate (Wynonie Harris and Louis Jordan come into mind first) but it had nothing to do with their output either.

People do not still listen to Thelonious Monk, Miles Davis and Charles Mingus because they were massively better than the pre-bop era musicians, it's simply because they are the first musicians which resemble modern jazz simply because they were hugely influential in creating it. It's also a bit of a "cultural fit" phenomenon often - if you give a listen to their recordings, they played far from perfection (just see all of those Monk recordings which are pretty much smashing the keys in a vaguely artistic manner), it has more to do with "namechecking" those fairly well-known musicians and signaling your in-group status by showing you listen to the "greats". If you go to a bunch of jazz musicians and say your favourite artist is Fats Waller or Hazel Scott, they'll either stare at you in a confused manner or laugh at you.

Also, trends from 80 or 100 years ago mean nothing now. For readers who are not in the "know" so much: music in those days radically changed decade to decade. The 40s was dominated by swing, the 50s was dominated by rock and roll, the 60s were dominated by doo-wop and mellower rock, etc... today, the landscape changes much slower, and tastes are much more heavily controlled by labels and algorithmic playlists. (Just check how "Hey Ya!" was seeded... and that was 20 years ago!)

Bad music is much less likely to disappear nowadays because listening to music is a much less conscious action by listeners. People usually put a playlist on Spotify and just listen to whatever comes up. Long gone are the days of buying records or CDs then putting them in your player to choose what you want to listen to. Songs in the 2020s are optimised for quick hooks so the listener doesn't skip. And the market forces actively work against weeding out mediocre music - in fact, artists are encouraged to become more mediocre to appeal to the widest possible audience by becoming so bland that it won't upset anyone. (the best example I can give is Caravan Palace - they started out as an electro-swing band but they make pop with some acoustic instruments at this point... their music is still good but heavily "streamlined")

In short, music streaming services and record companies have shifted from a more passive role to an active role of shaping music preferences and while this dynamic is ongoing, I would expect the current batch of mediocre music to persist. Things will only change once the social and technological aspects of listening to music change.